Captions & transcripts

Accessible content requires captions for video and transcripts for audio

Individuals with hearing impairments, especially those who are totally deaf, have difficulty understanding content that is only conveyed sonically. This includes all audio content and any video content that includes an audio component.

All videos that provide important information sonically should have accurate, synchronized captions, and all audio content should provide a full-text transcript.

Benefits

These measures allow individuals with hearing impairments to understand audio content, including audio-only materials and audio components for video content.

Best practices

Synchronized captions

All videos that have audio components should also maintain accurate, synchronized captions. Ideally, a user would be able to turn captions on or off based on need and preference.

Standards for captioning can be found on the DCMP Captioning Key website.

Full-text transcripts

All audio content should provide a full-text transcript, which should also include any audio content used as a part of a video. Transcripts are usually available on a separate web page or as a downloadable file.

Please see Creating accessible multimedia for more information on implementing captions and transcripts.

Checking for correct usage

Be sure to perform checks for the functionality of accessible measures:

View all the videos on the site with the captions activated and deactivated.
- Check that they are present and absent when appropriate.
- Verify they are accurate and synchronized properly with the video.
View the content with the audio muted to check that the content remains available and understandable.

Relevant standards

The Web Content Accessibility Guidelines (WCAG) are part of a larger accessibility initiative from the World Wide Web Consortium, the primary international standards organization for the Internet. These guidelines should be followed to strive for the best possible common accessibility.

WCAG 2.0 SC 1.2.1 (Level A) - Audio-only and Video-only (Prerecorded)
For prerecorded audio-only and prerecorded video-only media, the following are true, except when the audio or video is a media alternative for text and is clearly labeled as such:

Prerecorded Audio-only: An alternative for time-based media is provided that presents equivalent information for prerecorded audio-only content.
Prerecorded Video-only: Either an alternative for time-based media or an audio track is provided that presents equivalent information for prerecorded video-only content.

WCAG 2.0 SC 1.2.2 (Level A) - Captions (Prerecorded)
Captions are provided for all prerecorded audio content in synchronized media, except when the media is a media alternative for text and is clearly labeled as such.

WCAG 2.0 SC 1.2.4 (Level AA) - Captions (Live)
Captions are provided for all live audio content in synchronized media.